SAN FRANCISCO (AP) -- A massive replanting in Napa Valley of some of the world's priciest vineyards is so widespread a critical shortage of grapevine root stock has developed.

Giant suppliers such as Sunridge Nurseries in Bakersfield are taking orders for 2014 and beyond.

The shortage is due to a trifecta of developments. Aging cabernet vines planted after the deadly phylloxera outbreak across Napa Valley in the 1980s are due to be replaced. The reviving economy has created a surge in demand for premium grapes. And some growers are looking for clones and varieties better suited for their microclimates.
Mondavi alone is planting 1.5 million new vines.

Jennifer Putnam of Napa Valley Grapegrowers says the massive do-over, which will take place over many years, will allow them to raise the bar on quality.